Question

A high-tech company wants to estimate the mean number of years of college education its employees have completed. a good estimate of the standard deviation for the number of years of college is 1.41. how large a sample needs to be taken to estimate μ to within 0.51 of a year with 99% confidence? (round you answer up to the nearest whole number.)

Answer 1

The sample size n can be found as follows:
$0.51=2.576\times\frac{1.41}{ \sqrt{n} }$$\sqrt{n}=\frac{2.576\times1.41}{0.51}=7.12188$
$n=51$
The answer is: The sample size required is 51 employees.